At present, thin film transistor liquid crystal displays (TFT-LCD) have gradually occupied the predominance in the field of displays. A liquid crystal vertical alignment (Vertical Alignment, VA) technology is often adopted in the TFT-LCD to realize wide view angles. In the VA technology, a multi-domain vertical alignment (MVA) technology, an electrode pattern vertical alignment (PVA) technology and a polymer stabilized vertical alignment (Polymer Stabilized Vertical Alignment, PSVA) technology are developed according to different application occasions.
Similar to the other technology, the PSVA technology also needs a step of processing pre-tilt angle of liquid crystal molecules. Before this step, disordered liquid crystal molecules are arranged first in a certain form according to a designed electrode shape. Then, the arranged liquid crystal molecules are irradiated by adopting energy light such as ultraviolet for curing. In the above-mentioned process, no matter whether the alignment arrangement of the liquid crystal molecules is satisfying, the alignment condition of the liquid crystal molecules after being cured is completely memorized in a liquid crystal cell. If the arrangement of liquid crystal is poor during alignment, dark lines 101 shown in FIG. 1 may appear. It could be seen that, the dark lines are most obvious at the edges of each sub-pixel unit. This will reduce the efficiency of the liquid crystal, even result in non-uniform brightness of a display such as mura and the like, and thus affect the display of the LCD.
In the existing PSVA manufacturing process, there are many excuses for the poor tilt direction of the liquid crystal. For example, with respect to common electrodes in certain shapes, the edge electric fields generated by themselves are not as good as the middle electric fields, so that the arrangement condition of the liquid crystal molecules at the edges of each sub-pixel is less than satisfactory.
Therefore, with respect to the problem that the tilt direction of the liquid crystal molecules is not satisfying during processing liquid crystal molecule pre-tilt angle, there is a need for providing a new method to align liquid crystals for a PSVA liquid crystal display device.